CDVD: Comment out unreachable code.

-Left in so future checks can see what's going on.
-Coverity CID 146818: In ISOreadSector(unsigned char *, unsigned int, int): Code can never be reached because of a logical contradiction (CWE-561)

pcsx2/CDVD/CDVDisoReader.cpp

@@ -401,10 +401,10 @@ s32 CALLBACK ISOreadSector(u8* tempbuffer, u32 lsn, int mode)
 
 	switch (mode)
 	{
-		case CDVD_MODE_2352:
+		//case CDVD_MODE_2352:
 			// Unreachable due to shortcut above.
-			pxAssume(false);
-			break;
+		//	pxAssume(false);
+		//	break;
 
 		case CDVD_MODE_2340:
 			pbuffer += 12;